Latch



J. PICKLES Y Dec. 29, 1959 LATCH Filed Feb. 17, 1958 INVENTOR.

JOSEPH PICKLES ATTORNE FIG 2 United States Patent 01 LATCH Joseph Pickles, Dearborn, Mich., assignor to Ferro Stamping Company, Detroit, Mich, a corporation of Michigan Application February 17, 1958, Serial No. 715,630

23 Claims. (Cl. 292280) The present invention relates to a latch and more particularly, to a latch designed for use on the door of an automotive vehicle.

It is an object of the present invention to provide a latch of the wedge type characterized by its simplicity, the economy with which it may be produced, and the positive character of its action.

More specifically, it is an object of the present invention to provide a door latch having a rotary latching element connected to a camming rotor having a plurality of camming wedge portions, associated with a sliding wedge adapted to be frictionally gripped between a support and a cam surface of the camming rotor.

More specifically, it is an object of the present invention to provide structure as described in the preceding paragraph in which the support is mounted for movement toward and away from the cam rotor and is movable away from the cam rotor to effect unlatching of the latch rotor.

It is a feature of the present invention to provide latch mechanism comprising an elongated slide support pivoted adjacent one end, a toggle linkage for selectively rigidly supporting the other end of the slide support, a Wedge block slidable on the slide support having an inclined friction surface, a latch rotor, a camming rotor rigidly connected to the latch rotor having a plurality of lobes each of which is provided with a camming surface adapted to engage the friction surface of the wedge block.

It is a further feature of the present invention to provide structure as described in the preceding paragraph in which the camming surfaces of the lobes of the camming rotor are involute in shape.

Other objects and features of the invention Will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, illustrating a preferred embodiment of the invention, wherein:

Figure 1 is an elevational view of the latch structure showing the parts in the position attained when the door is open.

Figure 2 is a sectional view on the line 22, Figure 1.

Figure 3 is a fragmentary view similar to Figure 1 showing the parts in an intermediate position attained to movement of the door in closed position.

Figure 4 is a view similar to Figure 3 showing the parts in latching relation.

In the figures the operating elements of the latch are shown with cover plates removed so that the operating elements appear so far as possible in full lines. It will be appreciated that in an actual lock a cover plate will overlie the operating elements so that they are for the most part pivoted to mounting means extending transversely between laterally spaced plates.

As seen in Figure l, the latch comprises a base plate 10 to which is pivoted rotor structure including a latching rotor having a plurality of teeth one of which is indicated at 12. The latching rotor is at the opposite 2,919,152 Patented Dec. 29, 195.9

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side of the plate 10 from the structure adapted to hold the latching rotor in latching position and details of the latching rotor form no part of the present invention. Conveniently, the latching rotor may be provided with involute teeth in the form of gear teeth adapted to cooperate with a stationary keeper having a portion formed as a rack conjugate to the gear teeth of the latching rotor.

In accordance with the present invention mechanism is provided effective to prevent rotation of the latching rotor in the direction in which it is required to move as the door moves toward open position. This mechanism includes means moved against resilient means to a latching position and urged by the resilient means in a direction to take up lost motion and to maintain engagement in wedging relation to a camming rotor rigidly connected to the latching rotor.

As seen in Figure l the camming rotor is indicated at 14 and comprises a plurality, herein indicated as four, of camming lobes 16 each of which is provided with a camming surface 18 which as shown is an involute sur-v face from a base circle indicated in dot and dash lines at 20. The opposite sides of the lobes as indicated at 21 serve to engage the wedge as will subsequently be described, and to move it to operating position. The camming rotor 14 is rigidly connected to a pin 22 extending from the latching rotor and integral therewith or rigidly connected thereto.

Mounted for rocking movement about a pin 24 on the plate 10 is an elongated rail or bar 26. The free end of the bar is connected by means of a pin 28 to a link 30 of toggle mechanism which includes a bell crank 32 having a first arm 34 pivotally connected to link 30 by a pin 36, and a second actuating arm 38 pivotally connected by a pin 40 to an actuator 42.. The bell crank 32 is pivotally mounted on the plate 10 by means of a stationary pin 44 which also serves as the anchor for a spring 46 one end of which, as indicated at 48, engages the pin 40 and biases the bell crank 32 in a clockwise direction as seen in Figure 1. The plate 10 has a turned up abutment portion 50 engageable by one side of the bell crank arm 34. As observed in this figure, when the arm 34 engages the abutment 50 the toggle comprising the link 30 and the arm 34 of the bell crank is in over-center position such that forces applied to the bar 26 tending to swing it in a clockwise direction are inefiective.

Mounted on the elongated bar 26 for sliding movement thereon is a wedge block 52 having a down turned guiding flange 54 at one edge thereof and a tapered wedge portion 56 at the opposite edge. The wedge portion 56 has a friction surface 58 which is engageable with an involute camming surface 18 of one of the lobes 16 of the camming rotor 14.

Extending from the wedge block 52 is an eye 60 connected by a tension spring 62 to the fixed pivot pin 24 and operable to urge the wedge block 52 in a wedging direction or upwardly as seen in Figure l.

The rail or bar 26 is provided with shoulders 64 and- 66 which limit upward movement of the wedge block 52 to the position illustrated in Figure 1. This of course is the position occupied by the wedge block when the door is open.

Attention is directed to the fact that the wedge portion of the wedge block includes a surface 68 engageable with a side surface of the bar or rail 26 which is substantially opposed to its wedge surface 58. Accordingly, With the parts in operating position, the inclination of the wedging surface 58 may be substantially twice as great as it could be if only one pair of friction surfaces was effective, due to the combined effect of the two pairs of friction surfaces. The pairs of friction surfaces are of course the surface 68 coacting with the right edge of the rail 26, and the surfaces 18, 58. This in turn provides for control of the rotor 14 through a much greater arc than would otherwise be the case. Accordingly, as will subsequently appear, the mechanism is capable of retaining the door firmly againstopening movement throughout a; substantial arc and is operative through this are to exert a positive take-up action.

With the parts in the position illustrated in Figure 1 it may beassumed that the door is open, and that release of the handle or other suitable manipulating means associated with the actuator 42 has permitted the spring 48xto return the toggle mechanism including the link 30 and arm 34' to the over-center position illustrated in the figure. At the. same time, since the rail or bar 26 had been released to effect unlatching movement of the door, the wedgeblock 52 will have been returned by'the spring 62 to the limiting position against the shoulders 64 and As the door is moved toward closed position the teeth of its latching rotor engage the stationary keeper (not shown) and effect a counterclockwise rotation thereof and of the camming rotor 14 from the position illustrated in Figure 1. At this time it will be observed that the side 21 of a lobe 16 will engage the corner 70 of the wedge block 52 and will move it downwardly as seen in this figure to an intermediate position best illustrated in Figure 3. This is accomplished during a portion only of the final closing movement of the door so that when the tip of the particular lobe 16 which engages the corner 7i) of the wedge block is in position to move beyond the corner of the wedge block, the door is still not in fully or tightly closed position.

As seen in Figure 3, the tip of the lobe 16 is moving in the circular path indicated at 72 which at this point moves outwardly from the rectilinear path traced by the corner 70 of the wedge block. Accordingly, slight additional closing movement of the door from its position occupied when the latch elements are. in the relative position shown in Figure 3 will result in movement of the latching parts to the position illustrated in Figure 4. At this time it will be observed that the involute camming surface 18 of a lobe of the camming rotor is engaged in frictional contact with an intermediate portion of the wedge surface. 58 of the wedge block 52. This is the operating or latched condition in which the wedge block is effective to prevent opening movement of the door from its instantaneous position and in which, due to the action of the spring 62, it is effective to take-up instantly any lost motion or clearance resulting from. slight additional closing movement of the door. Accordingly, as the door may tend to vibrate slightly from the instantaneously substantially closed position, vibration toward open position is, prevented but vibration toward further fully closed position is permitted and the Wedge block moves to take-up the camming surface of the rotor so as to retain the door firmly latched in whatever further position of closing movement it attains. Thus, the lock is eifective' to prevent rattling and will retain the door solidly closed until released by actuation of the toggle mechanism.

The drawings and the foregoing specification constitute a description of the improved latch in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

1. A latch comprising a latching rotor, a cam rotor rigidly connected thereto and. having a plurality of cam lobes thereon, a bar disposed at the side of said cam rotor, a wedge block slidable on said bar, said wedge block having an inclined friction surface engaged by a cam surface of one of said lobes to prevent rotation of said rotors in the direction occasioned by door opening movement, resilient means connected to said wedge block.

to bias it to maintain its friction surface against the camming surface of one of said lobes, and releasable means supporting said bar against movement away from said cam rotor.

2. A latch comprising a latching rotor, a cam rotor rigidly connected thereto and having a plurality of cam lobes thereon, a bar pivoted atone end and disposed at the side of said cam rotor, a Wedge block slidable on said bar, said wedge block having an inclined friction surface engaged by a cam surface of-one of said lobes to prevent rotation of said rotors in the direction occasioned by door opening movement, resilient means connected to said Wedge block to bias it to maintain its friction surface against the camming surface of one of said lobes, and releasable means supporting said bar against movement away from said cam rotor.

3. A latch comprising a latching rotor, a cam rotor rigidly connected thereto and having a plurality of cam lobes thereon, a bar pivoted at one end and disposed at the side of said cam rotor, a wedge block slidable on said bar, said wedge block having an inclined friction surface engaged by a cam surface of one of said lobes to prevent rotation of said rotors in the direction 0c casioned by door opening movement, resilient means connected to said wedge block to bias it to maintain itsfriction surface against the camming surface of one of said lobes, and releasable toggle means supporting said bar against movement away from said cam rotor.

4. A latch comprising a latching rotor, a cam rotor rigidly connected thereto and having a plurality of cam lobes thereon, a bar disposed at the side of said cam rotor, a wedge block slidable on said bar, said wedge block having a wedge shaped portion provided with an inclined friction surface engaged by a cam surface of One of said lobes to prevent rotation of said rotors in the direction occasioned by door opening movement and a surface in slidable engagement With said bar, resilient means connected to said wedge block to bias it to maintain its friction surface against the camming surface of one of said lobes, and releasable means supporting said bar against movement away from said cam rotor.

5. Latching mechanism for a latch rotor comprising a cam rotor connected to said latch rotor, a bar pivotedat one end and disposed at a side of said cam rotor, a wedge block slidable on said bar and having an inclined friction surface facing said cam rotor, lobes on said cam rotor having cam surfaces engageable with said friction surface and preventing rotation of said cam rotor in door opening direction, resilient means biasing said wedge block on said bar in the direction to take up increments of rotation of said cam rotor in door closing direction, and releasable means for selectively retaining said bar in fixed position.

6. Latching mechanism for a latch rotor comprising a cam rotor connected to said latch rotor, a bar pivoted at one end and disposed at a side of said cam rotor, a wedge block slidable on said bar and having an inclined friction surface facing said cam rotor, lobes on said cam rotor having cam surfaces engageable with said friction surface and preventing rotation of said cam rotor in door opening direction, resilient means biasing said wedge block on said bar in the direction to take up increments of rotation of said cam rotor in door closing direction, and toggle means connected to the free end of said' bar for retaining it in fixed position and releasable to provide for movement of said bar away from said cam rotor to release said rotor. V

7. In a door latch, a plate, a cam rotor having a; plurality of cam. lobes having outwardly facing curved inclined' cam surfaces, a guide bar pivoted at one end to said plate and disposed for swinging movement toward and away from said rotor, a wedge block slidable on said bar having a wedge portion disposed between said bar. andsaid rotor, saidzwedge. block having, an inclined wedge surface engagedby the curved inclined cam. $11!:

face of one of said lobes, resilient means connectedto said wedge block and urging it in the direction to cause said wedge surface to follow the cam surface of the engaged lobe upon slight movement thereof in door closing direction.

8. In a door latch, a plate, a cam rotor having a plurality of cam lobes having outwardly facing curved inclined cam surfaces, a guide bar pivoted at one end to said plate and disposed for swinging movement toward and away from said rotor, a wedge block slidable on said bar having a wedge portion disposed between said bar and said rotor, said wedge block having an inclined wedge surface engaged by the curved inclined cam surface of one of said lobes, resilient means connected to said wedge block and urging'it in the direction to cause said wedge surface to follow the cam surface of the engaged lobe upon slight movement thereof in door closing direction, said block being movable from a limiting position by one of said lobes upon door closing movement, to an extreme position from which it is movable to cause its wedge surface to follow up'further door closing movement of said one lobe.

9. In a door latch, a plate, a cam rotor having a plurality of cam lobes having outwardly facing curved inclined cam surfaces, a guide bar pivoted at one end to said plate and disposed for swinging movement toward and away from said rotor, a wedge block slidable on said bar having a wedge portion disposed between said bar and said rotor, said wedge block having an inclined Wedge surface engaged by the curved inclined cam surface of one of said lobes, resilient means connected to said wedge block and urging it in the direction to cause said wedge surface to follow the cam surface of the engaged lobe upon slight movement thereof in door closing direction, said block being movable from a limiting position by one of said lobes upon door closing movement, to an extreme position from which it is movable to cause its wedge surface to follow up further door closing movement of said one lobe, and releasable blocking means connected between said plate and the other end of said bar.

10. In a door latch, a plate, a cam rotor having a plurality of cam lobes having outwardly facing curved inclined cam surfaces, a guide bar pivoted at one end to said plate and disposed for swinging movement toward and away from said rotor, a wedge block slidable on said bar having a wedge portion disposed between said bar and said rotor, said wedge block having an inclined wedgesurface engaged by the curved inclined cam surface of one of said lobes, resilient means connected to said wedge block and urging it in the direction to cause said wedge surface to follow the cam surface of the engaged lobe upon slight movement thereof in door closing direction, said block being movable from a limiting position by one of said lobes upon door closing movement, to an extreme position from which it is movable to cause its wedge surface to follow up further door closing movement of said one lobe, and releasable blocking means connected between said plate and the other end of said bar, said blocking means comprising over-center toggle mechanism.

11. In a door latch, a cam rotor having a plurality of lobes provided at one side thereof with outwardly facing curved inclined cam surfaces, a bar positioned at one side of said rotor for movement toward and away from said rotor, releasable blocking means connected to said bar to prevent movement thereof away from said rotor except when released, a wedge block slidable on said bar having an inclined wedge surface engageable by a cam surface of a lobe on said rotor, means connected to said block urging said block in wedging direction, said block having a portion positioned to be engaged by the end of one of said lobes to be moved thereby along said bar during door closing movement of the rotor against said resilient means to a position in which the end of its wedge surface more remote from'the axisof said rotor makes" lobes provided at one side thereof with outwardly facingcurved inclined cam surfaces, a bar positioned at one side of said rotor for movement toward and away from said rotor, releasable blocking means connected to said barto prevent movement thereof away from said rotor except when released, a wedge block slidable on said bar having an inclined wedge surface engageable by a cam surface of a lobe on said rotor, means connected to said block urging said block in wedging direction, said block having a portion positioned to be engaged by the end of one of said lobes to be moved thereby along said bar during door closing movement of the rotor against said resilient means to a position in which the end of its wedge surface more remote from the axis of said rotor makes initial contact with the camming surface of said one lobe, said resilient means being effective to draw said block in return direction as said rotor moves further in door closing direction.

13. Structure as defined in claim 12 in which said bar is pivoted.

14. Structure as defined in claim 12 in which said bar is pivoted and the releasable blocking means comprises.

over-center toggle mechanism.

15. Structure as defined in claim 14 which comprises spring means connected to said toggle mechanism to restore said bar to latching position when released.

16. Door latch mechanism comprising a lobed rotor rotatable in closing direction as the door moves from substantially closed into fully closed position and rotatable in opening direction as said door moves toward open from fully closed position, a wedge movable in a direction generally tangential of said rotor at the side thereof and having a wedge surface inclined to its direction of movement engageable with a lobe of said rotor to prevent opening rotation of said rotor, resilient means connected to said wedge urging it in wedging direction, said wedge being in position to be engaged by one side of a lobe of said rotor during final closing movement of the door and movable thereby against the action of said resilient means to a position in which said lobe releases said wedge for return movement in which its wedge surface confronts the other side of said one lobe, said resilient means being effective to cause return movement of said wedge to maintain said wedge surface in contact with said lobe and to follow up additional movement of said lobe in closing direction to keep the door tightly latched, a rail on which said wedge is movable, said rail being movable toward and away from said rotor, and releasable means normally preventing movement of said rail away from said rotor but rotatable to provide for such movement to release said rotor from the latching action of said wedge.

17. Door latch mechanism comprising a lobed rotor rotatable in closing direction as the door moves from substantially closed into fully closed position and rotatable in opening direction as said door moves toward open from fully closed position, a wedge movable in a direction generally tangential of said rotor at the side thereof and having a wedge surface inclined to its direction of movement engageable with a lobe of said rotor to prevent opening rotation of said rotor, resilient means connected to said wedge urging it in wedging direction, said wedge being in position to be engaged by one side of a lobe of said rotor during final closing movement of the door and movable thereby against the action of said resilient means to a position in which said lobe releases said wedge for return movement in which its Wedge surface confronts the other side of said one lobe, said resilient means being effective to cause return movement of said wedge to maintain said wedge surface in contact with said lobe and to follow up additional movement of said lobe in closing direction to keep the door tightly latched, a. raif on which said wedge is movable, said' rail.

tially' of said. rotor and having an inclined lateral wedge surface engaged by oneof the lobes of said rotor to prevent rotation. thereof in a direction occasioned by door-opening movement, an operator actuated mechanism connected to said wedge guide to move it away from said rotor to release positionto free said rotor for dooropening movement.

19 Latch mechanism comprising a support, a lobed. latch rotor pivoted on said support, a Wedge guide carried by said support for movement toward and away from said rotor between latching and release positions, a wedge movable on said" wedge guide generally tangentially of said rotor and having an inclined lateral Wedge surface engaged by one of the lobes of said rotor to prevent rotation thereof in a direction occasioned by door-opening movement, operator actuated mechanism.

connected to said-wedge guide to move it away from said rotor to release position to free said rotor for door-opening movement, and resilient means connected between said' support and said wedge guide effective to restore said Wedge guide to latching position when the operatoraotuated mechanism is released in door-open position.

20; Latch mechanism comprising a support, a lobed latch. rotor pivoted. on said support, a wedge guide carried by'said support for movement toward and away from said rotor between latching and release positions, a wedge movable on said wedge guide generally tangentially of said rotorand having an inclined lateral wedge surface engaged by one-of the lobes of said rotor to prevent rotation thereof in a direction occasioned by door-opening movement, operator actuated mechanism connected to said wedge guide to. move it away from said rotor to releaseposition to free said rotor for door-opening movement, andresilientmeans connected to said wedge to urge said. wedge in the direction to cause its wedge surfacev to move toward the axis of said rotor.

211. Latch mechanism comprising a support, a lobed latch rotor pivoted on said support, a wedge guide carried by said support for movement toward and away from said rotor between latching and release positions, a wedge movable on. said; wedge guide generally tangentially of said ro'tor andhaving an inclined lateral wedge surface engaged by one of the lobes of said rotor to prevent rotation. thereof in a direction occasioned by door-opening movement, operator actuated mechanism connected to said wedge guide to move it away from said rotor tore-- lease positionito free said rotor for door-opening move ment, resilient means connected to said wedge to urge' said wedge in thedirection to cause its wedge surface to move toward the axis of said rotor, and abutment means limiting movement of said wedge on said wedge guide by. said resilient meansto a position in which r0 tation of said rotor occasioned by door-closing movement causes the leading side of one lobe to shift said wedge away from its abutment-limited position to a position attained near the end of door-closing movement in vwhich the wedge surface of said wedge moves into engagement with the trailing side of said one lobe.

22. Latch mechanism comprising asupport, a lobed latch rotor pivoted on said support, a wedge guide carried by said support for movement toward and away from movement, operator actuated mechanism connected to:-

said wedge guide to move it away from said rotor to release position to free said rotor for door-opening movement, resilient means'connected to said wedge to urge said wedge in the direction to cause its wedge surface to move toward the axis of said rotor, and abutment means limiting movement of said wedge'on said wedge guide by said resilient means to a position in which rotation of said rotor occasioned by door-closing movement causes the leading side of one lobe to engage an end surface of said wedge and to thereby shift said wedge away from its abut- 1 merit-limited position to aposition attained near the end of door closing movement in which the wedge surface of said wedge moves into engagement with the trailing side of said one lobe.

23; Latch mechanism comprising a support, a lobed latch roto'r pivoted on said support, a wedge guide bar pivotally carried by said support for movement toward and away from said rotor between latching and release positions, a wedge movablev on said wedge guide bar generally tangentially of said rotor and having an inclined lateral wedge surface engaged by one of the lobes of said rotor to prevent rotation thereof in a direction occasioned by door-opening movement, and operator actuated mechanism connected to said Wedge guide bar to move it away from said rotor to release position to free said rotor for door-opening movement.

References Cited in the'file of this patent UNITED STATES PATENTS 

